The wide diffusion of image processing apparatuses has enabled anyone to easily copy or transmit a document. This has offered the user an increase in convenience but at the same time has increased the possibility of information leaking-out, such as by copying or transmission of a confidential document or the like.
To cope with the problem, there is proposed an image processing apparatus which accumulates, in a storage device, all of image data to be copied or transmitted, in addition to a user ID (National Publication of International Patent Application No. 1998-503901). This makes it possible to chase to find out track which user has copied or transmitted a document with leaked-out information.